R Programming - Find Row and Column Index of Max/Min values in a Matrix

R Programming: Matrix Exercise-11 with Solution

Write a R program to find row and column index of maximum and minimum value in a given matrix.

Sample Solution:

R Programming Code:

# Create a 4x4 matrix with values from 1 to 16, filled by row
m = matrix(c(1:16), nrow = 4, byrow = TRUE)

# Print a message indicating that the following output is the original matrix
print("Original Matrix:")

# Print the original matrix
print(m)

# Find the row and column indices of the maximum value in the matrix
result = which(m == max(m), arr.ind=TRUE)

# Print a message indicating that the following output is the row and column of the maximum value
print("Row and column of maximum value of the said matrix:")

# Print the indices of the maximum value
print(result)

# Find the row and column indices of the minimum value in the matrix
result = which(m == min(m), arr.ind=TRUE)

# Print a message indicating that the following output is the row and column of the minimum value
print("Row and column of minimum value of the said matrix:")

# Print the indices of the minimum value
print(result)

Output:

[1] "Original Matrix:"
     [,1] [,2] [,3] [,4]
[1,]    1    2    3    4
[2,]    5    6    7    8
[3,]    9   10   11   12
[4,]   13   14   15   16
[1] "Row and column of maximum value of the said matrix:"
     row col
[1,]   4   4
[1] "Row and column of minimum value of the said matrix:"
     row col
[1,]   1   1                

Explanation:

• Create a Matrix:
• m = matrix(c(1:16), nrow = 4, byrow = TRUE)
• Creates a 4x4 matrix named m with values from 1 to 16, filling the matrix by rows.
• Print Original Matrix:
• print("Original Matrix:")
• Prints the label "Original Matrix:" to indicate that the following output is the original matrix.
• print(m)
• Prints the content of the matrix m.
• Find Maximum Value Index:
• result = which(m == max(m), arr.ind=TRUE)
• Finds the indices (row and column) of the maximum value in the matrix m.
• arr.ind=TRUE returns the indices in array format.
• Print Maximum Value Indices:
• print("Row and column of maximum value of the said matrix:")
• Prints the label indicating that the following output shows the row and column indices of the maximum value.
• print(result)
• Prints the indices of the maximum value.
• Find Minimum Value Index:
• result = which(m == min(m), arr.ind=TRUE)
• Finds the indices (row and column) of the minimum value in the matrix m.
• arr.ind=TRUE returns the indices in array format.
• Print Minimum Value Indices:
• print("Row and column of minimum value of the said matrix:")
• Prints the label indicating that the following output shows the row and column indices of the minimum value.
• print(result)
• Prints the indices of the minimum value.

R Programming Code Editor:

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